src/webkit/browser/blob/blob_data_handle.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "webkit/browser/blob/blob_data_handle.h"
   6
   7 #include "base/bind.h"
   8 #include "base/location.h"
   9 #include "base/logging.h"
  10 #include "base/sequenced_task_runner.h"
  11 #include "webkit/browser/blob/blob_storage_context.h"
  12 #include "webkit/common/blob/blob_data.h"
  13
  14 namespace webkit_blob {
  15
  16 BlobDataHandle::BlobDataHandle(BlobData* blob_data, BlobStorageContext* context,
  17                                base::SequencedTaskRunner* task_runner)
  18     : blob_data_(blob_data),
  19       context_(context->AsWeakPtr()),
  20       io_task_runner_(task_runner) {
  21   // Ensures the uuid remains registered and the underlying data is not deleted.
  22   DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
  23   context_->IncrementBlobRefCount(blob_data->uuid());
  24   blob_data_->AddRef();
  25 }
  26
  27 BlobDataHandle::~BlobDataHandle() {
  28   if (io_task_runner_->RunsTasksOnCurrentThread()) {
  29     // Note: Do not test context_ or alter the blob_data_ refcount
  30     // on the wrong thread.
  31     if (context_.get())
  32       context_->DecrementBlobRefCount(blob_data_->uuid());
  33     blob_data_->Release();
  34     return;
  35   }
  36
  37   io_task_runner_->PostTask(
  38       FROM_HERE,
  39       base::Bind(&DeleteHelper, context_, base::Unretained(blob_data_)));
  40 }
  41
  42 BlobData* BlobDataHandle::data() const {
  43   DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
  44   return blob_data_;
  45 }
  46
  47 // static
  48 void BlobDataHandle::DeleteHelper(
  49     base::WeakPtr<BlobStorageContext> context,
  50     BlobData* blob_data) {
  51   if (context.get())
  52     context->DecrementBlobRefCount(blob_data->uuid());
  53   blob_data->Release();
  54 }
  55
  56 }  // namespace webkit_blob